1. Field of the Invention
The present invention relates to message management in a wireless selective call receiver. More particularly, the present invention relates to message management in a wireless selective call receiver, in which a plurality of messages can be stored in a RAM, and one of the plurality of messages to be deleted can be specified based on the attributes of the messages when the storage capacity of the RAM is full.
2. Description of the Related Art
Conventionally, in the message management in a wireless selective call receiver, each of the messages stored in a RAM is added with protection information indicative of whether the message should be protected, as described in, for example, Japanese Laid Open Utility Model Disclosure (JU-A-Showa 64-54437). In the method, the messages other than the message which should be protected are deleted in accordance with the protection information in a predetermined order, in the case that to empty storage area of the RAM is not present.
FIG. 1A shows a storage mapping diagram of the RAM when management of messages is performed in the conventional wireless selective call receiver. In this example, the number of messages which can be stored in the RAM is 10. That is, ten messages are stored in the storage locations of the message number 0 to the message number 9 in the RAM. When a message is received in the state that any message is not stored in the RAM, the received message is stored in order from the message number 0. When a message is stored in the message number 9 of the RAM, empty storage area is not present.
A message protection flag is provided for each message. The message protection flag is set through a switch operation by a user. In FIG. 1A, messages A-J are stored in the storage locations of the message numbers 0-9 and the messages with the message numbers 0, 1, 4 and 8 are protected.
Next, the processing procedure in the method of managing messages in the conventional wireless selective call receiver is shown in FIG. 1B.
First, when a message issued to the receiver is received (Step S21), it is determined whether or not any empty storage area is present in the message storage RAM (Step S22). If any empty storage area is present, the received message is stored in a storage location with the smallest message number in the empty storage area (Step S23). Then, the processing ends.
On the other hand, when it is detected that there is no empty storage area in the processing of the step S22, the search of a message to be is performed. For this purpose, 0 is set in a variable a for the search of this message to be deleted (Step S24). Then, it is determined whether or not the message with the message number a=0 is a protected message (Step S25). When the message with the message number a=0 is one of the protected messages, 1 is added to the message number a and then the control returns to the step S25 (S26). Subsequently, it is determined in the processing of the step S25 whether or not the message with the message number a=1 is a protected message. This operation is repeated until the message which is allowed to be deleted is found out.
When a message which is allowed to be deleted, that is, does not have a protection flag set is found out in the processing of the step S25, the message with the message number a is deleted (Step S27).
Next, nine remaining messages are rearranged in the storage locations of the message numbers 0 to 8 in the order of older reception time to set the message number 9 to an empty storage location (Step S28). Subsequently, the control advances to the processing of the step S22 and already received message is stored in the RAM in accordance with the processing procedure of the steps S22 and S23. Then, the processing is ended.
There are the following problems in the case of message management in the conventional wireless selective call receiver. The first problem is in that already received call messages to the user himself and so on are deleted when the receiver is set in the operating state without any switch operation and information messages such as news, weather forecast and so on are continuously received. The reason is that the protection of the message can not be performed when the receiver is set in the operating state, because the message protection is executed through a switch operation by the user.
Also, the second problem is in that when information messages with the same attribute are continuously received, the RAM is filled only with the information message with the same attribute. This is because the message to be deleted when the RAM does not have any empty storage area is determined based on the existence or non-existence of the protection designation of each of the stored messages and the reception times of the messages.
In addition to the above reference, a protecting and deleting method of a data in a receiver is described in Japanese Laid Open Patent Disclosure (JP-A-Showa 62-268220). In this reference, when a message with an ID is received and a storage unit is full, a message allowed to be deleted is searched. When the message to be deleted is found, the message is deleted and then the message and the ID are stored. When any message allowed to be deleted is not found, only the ID is stored.
A memory managing system is described in Japanese Laid Open Patent Disclosure (JP-A-Heisei 6-303336). In this reference, a memory 4 for storing messages is divided into a first storage section 4-1 and a second storage section 4-2. Messages from predetermined telephone numbers are stored in the first storage section and the other messages are stored in the second storage section. Alternatively, identification information is added to the messages from the predetermined telephone numbers which are stored in the memory 4 after the messages from the other telephone numbers are deleted.
A speech and data transmission terminal apparatus which is connected to a center apparatus is described in Japanese Laid Open Patent Disclosure (JP-A-Heisei 3-40651). In this reference, a control unit has a function to determine an empty storage area of an information storage medium, and a function to request the stopping of transmission of data to the center apparatus when empty storage area is not present. The control unit has a function to delete a designated content from the information storage medium to prepare an empty storage area and a function to store a received data in the empty storage area.
An information protecting method is described in Japanese Laid Open Patent Disclosure (JP-A-Heisei 7-79464). In this reference, a keyword is prepared to specify a message to be protected. When a received message has the same word portion as the keyword from the head, the received message is stored in a memory.